Field
Embodiments of the present disclosure generally relate to valves capable of withstanding high pressures, including valves for use in hydrocarbon wells for artificial lift operations.
Description of the Related Art
To obtain hydrocarbon fluids from an earth formation, a wellbore is drilled into the earth to intersect an area of interest within a formation. The wellbore may then be “completed” by inserting casing within the wellbore and setting the casing therein using cement, for example. In the alternative, the wellbore may remain uncased (an “open hole” wellbore), or may be only partially cased. Regardless of the form of the wellbore, production tubing is typically run into the wellbore primarily to convey production fluid (e.g., hydrocarbon fluid, as well as water and other, non-hydrocarbon gases) from the area of interest within the wellbore to the surface of the wellbore.
Often, pressure within the wellbore is insufficient to cause the production fluid to rise naturally through the production tubing to the surface of the wellbore. Thus, to force the production fluid from the area of interest within the wellbore to the surface, artificial lift means are sometimes employed. Gas lift is an example of artificial lift means for increasing production of oil and gas from a wellbore.
Gas lift systems are often the preferred artificial lifting systems because operation of gas lift systems involves fewer moving parts than operation of other types of artificial lift systems, such as sucker rod lift systems. Moreover, because no sucker rod is required to operate the gas lift system, gas lift systems are usable in offshore wells having subsurface safety valves that would interfere with a sucker rod.
Gas lift systems commonly incorporate one or more valves in side pocket mandrels of the production tubing to enable the lifting of production fluid to the surface. Ideally, the gas lift valves allow gas from the annulus between the casing and production tubing to enter the tubing through the valves, but prevent reverse flow of production fluid from the tubing to the annulus.
One type of gas lift valves are injection pressure operated gas lift valves which generally include a bellows to convert pressure from the injection gas into movement. However, the pressure in the injection gas is much higher than working pressure of the bellows. To protect the bellow, entrapment of a liquid on one side of the bellows is usually used to act against the injection gas pressure from an opposite side of the bellows. However, gas bubbles are sometimes trapped in the liquid during operation and damage the bellows. Traditionally, a high viscosity liquid is generally used in the injection pressure operated gas lift valves to dampen valve chatter. However, because gas lift valves usually operates a high temperature of up to 300° F., viscosity of the liquid reduces significantly leaving valve chattering untamed.
Therefore, there is a need for apparatus and methods to provide bellow protection and to reduce chattering in lift valves.